The invention relates to a coding/decoding method for a deinterleaver, and in particular to a coding/decoding method for a deinterleaver which converts a television signal to image data.
This section is intended to introduce the reader to various aspects of the art, which may be related to various aspects of the invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of related art.
Generally, during transmission for digital television, image data to be transmitted is encoded, and the encoded image data is transmitted through wireless signals. After the wireless signals are received by the digital television, the encoded data is then decoded, and converted to image data, which is then displayed on the television screen.
Referring to FIG. 1(a), image data for a digital television is displayed. As shown in FIG. 1(a), image data 1 comprises a system part 11 and a data part 12. When the image data 1 is transmitted via wireless directly, interference during the wireless transmission process may cause abnormal peaks in the image data 1. The abnormal peak causes damage to signals of a portion of continuing system part 1 or data part 12. It is difficult to recover the damaged signals after which are received by a digital television. When the image data is displayed, the damaged part of the image cannot be displayed correctly. If the system part of the image data is damaged, the image data cannot not be displayed. Accordingly, when image data is transmitted, the image data is encoded, i.e., arranged in a non-contiguous way. Referring to FIG. 1(b), encoded image data 2 comprises system part 21 and data part 22, wherein the system part 21 is divided into several segments, each arranged in different position, followed by discontinuous data part 22. If interference occurs during the transmission of image data 2, since data of image data 2 is arranged in a non-contiguous way, data damaged by the interference is not contiguous, accordingly. It is easier to recover the damaged data after received. Accordingly, image data is encoded before it is transmitted.
Formulae are utilized in encoding/decoding process of image data. In the encoding process, segments of the image data are arranged in different positions according to a formula. In the decoding process, the image data is recovered from the discontinuous rearranged segments according to a formula. Two conventional methods are used for calculation of the formulae. According to one conventional method, a look-up table in a database stores calculation results in advance, for retrieval when required. One disadvantage of this conventional method is that considerable storage capacity is required to store the data. According another conventional method, computing hardware is utilized, using adder and multiplier hardware to perform calculations to obtain a calculation result. One disadvantage of this method is that considerable calculation is required, consuming computing time, hardware resources, and cost.